1. Field of the Invention
The present invention relates to a chemical mechanical polishing slurry and a method of manufacturing a semiconductor device by using the same.
2. Description of the Related Art
A buried wiring (damascene wiring) technology is being studied and developed in recent years as a wiring technology in a semiconductor VLSI in order to simplify the wiring process and to improve the yield and the reliability of the wiring. For forming a damascene wiring, a chemical mechanical polishing (CMP) technology constitutes an indispensable important technology.
When it comes to a damascene wiring used widely nowadays, copper having a low resistivity is used mainly as a wiring metal in a high-speed logic device. Aluminum or tungsten is used as a wiring metal in a memory device represented by a DRAM because of the low cost. However, in any of the devices, aluminum having a resistivity nearly close to that of copper is expected to provide a hopeful damascene wiring metallic material in view of both the low resistivity and the low cost.
In the CMP technology, a high polishing rate of the wiring metal, a planarity of the polished surface, and a low defect density on the polished surface are required. However, since the aluminum film is softer than the other damascene wiring metal film such as a copper film or a tungsten film, problems such as, particularly, the scratch and the surface roughness tend to be generated, if a CMP treatment is carried out by using a slurry containing inorganic particles, e.g., alumina particles, as the polishing abrasive grains. The generation of the scratch and the surface roughness markedly lowers the yield of the wiring.
In order to suppress, e.g., the scratch generation in the wiring metal such as aluminum, it is known to the art that a CMP slurry containing resin (polymer) particles mixed with inorganic particles such as alumina particles is used for the CMP treatment, as disclosed in, for example, Japanese Patent Disclosure (Kokai) No. 2000-269169, Japanese Patent Disclosure No. 2000-269170, Japanese Patent Disclosure No. 2001-15462, and Japanese Patent Disclosure No. 2002-30271.
However, it has been found by the research conducted by the present inventor that it is difficult to simultaneously achieve a high polishing rate, a low erosion, a reduced scratch and/or a reduced surface roughness in the case where a CMP treatment is applied to an aluminum film by using the conventional CMP slurry noted above, which contains inorganic particles such as alumina particles and resin (polymer) particles.